package com.yzg.pool;

import lombok.extern.slf4j.Slf4j;

import java.sql.*;
import java.util.Map;
import java.util.Properties;
import java.util.Random;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicIntegerArray;

/**
 * @author misterWei
 * @create 2020年05月31号:18点42分
 * @mailbox forcontinue@163.com
 */
@Slf4j(topic = "c.DriverPool")
public class DriverPool {
    public static void main(String[] args) {
        DriverConnections driverConnections = new DriverConnections(2);
        for (int i = 0; i < 5; i++) {
            new Thread(()->{
                Connection connection = driverConnections.get();
                try {
                    Thread.sleep(new Random().nextInt(1000));
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }finally {
                    driverConnections.restitution(connection);
                }

            },"t "+ i).start();
        }

    }
  static final class DriverConnections {
      /**
       * 链接大小
       */
     private  final int poolSize;
      /**
       * 数组
       */
      private Connection[] connections;
      /**
       * 数组状态 0 代表空闲 , 1 代表占用
       */
      private AtomicIntegerArray status;

      public DriverConnections(int poolSize) {
          this.poolSize = poolSize;
          this.connections = new Connection[poolSize];
          this.status = new AtomicIntegerArray(new int[poolSize]);
          for (int i = 0; i < poolSize; i++) {
              this.connections[i] = new DriverConnection();
          }
      }

      /**
       * 得到
       */
      public Connection get(){
          for (;;){
              for (int i = 0; i < poolSize; i++) {
                  int temp = this.status.get(i);
                  if (temp == 0){
                      if (this.status.compareAndSet(i,temp,1)) {
                          //修改成功
                          log.info("获取成功!{}",connections[i]);
                          return this.connections[i];
                      }
                  }
              }
            //进入等待
              synchronized (this){
                  try {
                      //等待 5秒
                      log.info("wait...");
                      this.wait(TimeUnit.SECONDS.toMillis(5));
                  } catch (InterruptedException e) {
                      e.printStackTrace();
                  }
              }
          }
      }

      /**
       * 归还
       */
      public void restitution(Connection conn){
          for (int i = 0; i < poolSize; i++) {
              if (connections[i] == conn) {
                  status.set(i,0);
                  synchronized (this){
                      notifyAll();
                  }
                  break;
              }
          }

      }
  }

    /**
     * 自定义实现子类
     */
    static class DriverConnection implements Connection{

    @Override
    public Statement createStatement() throws SQLException {
        return null;
    }

    @Override
    public PreparedStatement prepareStatement(String sql) throws SQLException {
        return null;
    }

    @Override
    public CallableStatement prepareCall(String sql) throws SQLException {
        return null;
    }

    @Override
    public String nativeSQL(String sql) throws SQLException {
        return null;
    }

    @Override
    public void setAutoCommit(boolean autoCommit) throws SQLException {

    }

    @Override
    public boolean getAutoCommit() throws SQLException {
        return false;
    }

    @Override
    public void commit() throws SQLException {

    }

    @Override
    public void rollback() throws SQLException {

    }

    @Override
    public void close() throws SQLException {

    }

    @Override
    public boolean isClosed() throws SQLException {
        return false;
    }

    @Override
    public DatabaseMetaData getMetaData() throws SQLException {
        return null;
    }

    @Override
    public void setReadOnly(boolean readOnly) throws SQLException {

    }

    @Override
    public boolean isReadOnly() throws SQLException {
        return false;
    }

    @Override
    public void setCatalog(String catalog) throws SQLException {

    }

    @Override
    public String getCatalog() throws SQLException {
        return null;
    }

    @Override
    public void setTransactionIsolation(int level) throws SQLException {

    }

    @Override
    public int getTransactionIsolation() throws SQLException {
        return 0;
    }

    @Override
    public SQLWarning getWarnings() throws SQLException {
        return null;
    }

    @Override
    public void clearWarnings() throws SQLException {

    }

    @Override
    public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException {
        return null;
    }

    @Override
    public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
        return null;
    }

    @Override
    public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
        return null;
    }

    @Override
    public Map<String, Class<?>> getTypeMap() throws SQLException {
        return null;
    }

    @Override
    public void setTypeMap(Map<String, Class<?>> map) throws SQLException {

    }

    @Override
    public void setHoldability(int holdability) throws SQLException {

    }

    @Override
    public int getHoldability() throws SQLException {
        return 0;
    }

    @Override
    public Savepoint setSavepoint() throws SQLException {
        return null;
    }

    @Override
    public Savepoint setSavepoint(String name) throws SQLException {
        return null;
    }

    @Override
    public void rollback(Savepoint savepoint) throws SQLException {

    }

    @Override
    public void releaseSavepoint(Savepoint savepoint) throws SQLException {

    }

    @Override
    public Statement createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
        return null;
    }

    @Override
    public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
        return null;
    }

    @Override
    public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability) throws SQLException {
        return null;
    }

    @Override
    public PreparedStatement prepareStatement(String sql, int autoGeneratedKeys) throws SQLException {
        return null;
    }

    @Override
    public PreparedStatement prepareStatement(String sql, int[] columnIndexes) throws SQLException {
        return null;
    }

    @Override
    public PreparedStatement prepareStatement(String sql, String[] columnNames) throws SQLException {
        return null;
    }

    @Override
    public Clob createClob() throws SQLException {
        return null;
    }

    @Override
    public Blob createBlob() throws SQLException {
        return null;
    }

    @Override
    public NClob createNClob() throws SQLException {
        return null;
    }

    @Override
    public SQLXML createSQLXML() throws SQLException {
        return null;
    }

    @Override
    public boolean isValid(int timeout) throws SQLException {
        return false;
    }

    @Override
    public void setClientInfo(String name, String value) throws SQLClientInfoException {

    }

    @Override
    public void setClientInfo(Properties properties) throws SQLClientInfoException {

    }

    @Override
    public String getClientInfo(String name) throws SQLException {
        return null;
    }

    @Override
    public Properties getClientInfo() throws SQLException {
        return null;
    }

    @Override
    public Array createArrayOf(String typeName, Object[] elements) throws SQLException {
        return null;
    }

    @Override
    public Struct createStruct(String typeName, Object[] attributes) throws SQLException {
        return null;
    }

    @Override
    public void setSchema(String schema) throws SQLException {

    }

    @Override
    public String getSchema() throws SQLException {
        return null;
    }

    @Override
    public void abort(Executor executor) throws SQLException {

    }

    @Override
    public void setNetworkTimeout(Executor executor, int milliseconds) throws SQLException {

    }

    @Override
    public int getNetworkTimeout() throws SQLException {
        return 0;
    }

    @Override
    public <T> T unwrap(Class<T> iface) throws SQLException {
        return null;
    }

    @Override
    public boolean isWrapperFor(Class<?> iface) throws SQLException {
        return false;
    }
}


}
